kesling



March 18, 1958 E. G. KEsLlNG 2,827,234

ANTISPINNING CONSTRUCTION FOR ROTARY DIAL ADDERS Filed March l2, 1956 5Sheets-Sheet l @TroreA/EYS mw S ummm. Sv www ww mw ww Ew E m MW@ n R mmm uw E'. G. KEsLlNG 2,827,234

`March 18, 11958 Y ANTI-SPINNING CONSTRUCTION FOR ROTARY DIAL AOOERS 5sheetsh-Shee't 2 Filed March 12,4 1956 :GJ www TL d E um N K M M6 T E L5 d,

March 18, 1958 E. VG. KEsLlNG 2,827,234

ANTI-SPINNING CONSTRCTION FR ROTARY DIAL ADDERS Filed March l2, 1956 3Sheets-Sheet 5 @www United States Patent O ANTI-SPHNNING QNSTRUCTIN FRROTARY DAL ADDERS Eimer G. Kesling, Richmond Heights, Mo. ApplicationMarch 12, 1956, Serial N o. 571,103 15 Claims. (Cl. 23S- 74) The presentinvention relates generally to portable calculators, and moreparticularly to a pocket calculator incorporating a novel anti-spinningconstruction which prevents unintended movement of dials during periodswhen they are released from normal detent control.

Calculators having a multiplicity of rotary dials, including separatedials for units, tens, hundreds, etc., are widely known and have a basicmode of operation which is generally well-understood. It is with aspecific requirement of the basic mode of operation that the presentinvention is involved, namely, the requirement for release from normaldetent control of dials of higher number than the one operated so as toenable the released dials to be appropriately indexed in accordance withthe demands of the particular computation.

Whereas, normally, the several dials of the pocket calcul-ator hereconsidered are maintained against inadvertent rotation by means ofeilicient detent mechanism, it has been found that the necessity forreleasing certain of these dials for the purpose above-mentioned leavesthem momentarily susceptible to uncontrolled rotation. For example, anindexing pulse from an adjacent dial may be of suilcient force to causethe indexed dial to spin past the intended position, which will, ofcourse, produce an error in the computation.

It is an object of the present invention, therefore, to provide a novelanti-spinning mechanism which maintains interlocked cooperation betweenadjacent dials so as to inhibit the spinning of a dial as it is indexed.

lt is another object of the present invention to provide a novelmechanism for controlling the rotation of one dial through aninterlockingy connection with an adjacent dial.

It is another object of the invention to provide a novel anti-spinningmechanism which incorporates a rockable lever adapted to cooperate withadjacent rotary dials.

It is another object of the invention to provide a pocket calculatorwhich incorporates novel anti-spinning mechanism for controlling themovement of released dials.

The foregoing, along with additional objects and advantages, will be`apparent from the following description of a speciic embodiment of theinvention taken with the accompanying drawings illustrating the same. Inthe drawings:

Figure l is a plan view of a pocket calculator incorporating theteachings of the present invention;

Figures 2 and 3 are vertical longitudinal sections taken substantiallyalong the lines 2-3 of Figure 1, but drawn to an enlarged scale;

Figure 4 is a horizontal plan view of the calculator similar to Figurel, but with the cover removed and with certain parts and portions ofparts removed and sectioned in a manner to indicate clearly theassembled relation of parts in the device;

Figure 5 is a horizontal cross-sectional view drawn to an-enlarged scaleand showing a fragmentary portion of the calculator;

Figure 6 is a fragmentary vertical section taken generally along theline 6-6 of Figure 5;

Figure 7 is a vertical elevation of a removed dial;

Figure 8 is a horizontal bottom view of the removed dial;

Figure 9 is a horizontal plan view of a removed detent plate drawn toreduced scale;

Figure 10 is an enlarged fragmentary vertical section showing theright-hand end of a calculator incorporating a modified arrangement ofthe present invention;

Figure ll is a fragmentary horizontal sectional view showing a portionof the right-hand end of the calculator of Figure l0 with its coverremoved;

Figure l2 is a fragmentary vertical section taken generally along theline 12-12 of Figure 1l;

Figure 13 is a horizontal bottom view of a removed dial of the typeemployed in the calculator of Figure l0;

Figure 14 is a fragmentary vertical section taken along the line 14-14of Figure 13 g and Figure l5 is a bottom plan view of an idler gear.

Referring to the drawings more particularly by reference numerals, anddirecting attention first to Figures l through 9, 2i) indicatesgenerally a calculator incorporating the teachings of the presentinvention. In its broad aspects, the calculator 20 includes a case 21comprising a base 22 and a cover 24, dial members 27 for units, tens,hundreds, etc., a detent 28 and detent spring 29, idler gears 30, androcking levers 32. Preferably, the components of the calculator 20 aremade of plastic material, with the exception of the spring 29 employedfor the detent 23. Conventional cross-hatching is used in the drawingsin the interest of clarity of illustration.

The base 22 is generally rectangular in form and includes a bottom 4l),side walls 41 and 42 `and end walls 43 and d4. Extending upwardly fromthe bottom 49 are equally spaced integral posts 45 which rotatablysupport the dial members 27, as illustrated. The posts 45 slope slightlyin the longitudinal direction of the base 22, but are at right angles tothe latter when viewed lengthwise. Each post 45 has a well 46 for apurpose which appears below. There are six posts 4S in the presentcalculator 20, although a greater or a lesser number may be used, and toone side of each, except the right-hand one, viewing Figure 3, is anintegral post 4S having an annular reduced neck 49 inset by a slopingshoulder which rotatably receives a reversing or idler gear 30, asillustrated. Referring to Figures 4, 5 and 6, spaced to the right andabove each post 43 there is an integral post 5d having an. odset annularreduced neck 5l for pivotally receiving a rocking lever 32, asillustrated. Finally, in the upper right hand corner of the bottom 40 isan integral post 53 for anchoring the detent spring 29. Au elongatedrecess 54 is formed in the bottom 4i) for accommodation of the detentspring 29.

Each dial member 27 includes an upper disc dial portion 58, a lower discportion 59 of smaller' diameter thany the disc portion 58 having atransfer finger 6), a cam portion 61 provided with a plurality ofangularly spaced notches 62 and with one elongated notch 63 as clearlyillustrated in Figure 8, and a gear portion 64 comprising ten teeth 65spaced equidistantly, as also illustrated'in Figure 8. A cylindricalopening 66 extends through the dial member 27 by means of which it isfreely rotatably' mounted upon its respective post 45 (Figures 2 and 3.)

Adjacent the periphery of the upper face of the dial portion 58 areequi-spaced counterclockwise numbers ll through 9, and 0, and midwaybetween and inwardly ot' each pair of numbers is a Well 67 for receivinga stylus or pencil point. Preferably, the dial members 27 are ofintegral construction.

and is engageable at its right side by a transfer finger 60. Theillustrated detent plate having elongated openings 68 therein, each ofNote thatl an idler gear 3l) engages each gear portion 64, except theright-hand one,-

28 is in 'the form of a ilat' which is-lrgeenoughtt'o receive a gearportion 64 and an idler gear in a manner to permit free longitudinalmovement of the detent 28. Elongated openings 69 are provided whichreceive the several posts 5t) above mentioned. The elongated openingsenable the det'ent 28 to'have limited reciprocal movement longitudinallyof the calculator 26, and it is preferred that the lateral width of thetwo elongated openings nearest each end of the detent 28 be sized forguiding the reciprocating movements of the member 2S. Further, it ispreferred that the intermediate openings 69 be of ample size to clearthe associated posts 5) so as to avoid any possibility of frictionalbinding at these points.

Referring further to the detents 23, a plurality of detent angles areformed, one each for engagement with the upper part of the gear portioned of the respective dial members 27. Itis tobe noted that the detentangles 7i) are at an increasing angle from right to left, as clearlyillustrated in Figure 9, which is a relationship originally disclosed inapplicants Patent No. 2,588,539.

Referring to Figures 4 and 5, the detent 28 is biased into engagementwith the gear portions 64 by the detent spring 29, one end of which ishooked into the end wall of the rightmost elongated opening 69 and theother end of which is secured to the post 53 formed integral with thebottom 40 of the base 22.

Asbest shown in Figure 6, the posts 59 have flat surfaces 72 upon whichthe rocking levers 32 rest. This surface 2 is normal to the axis of thepost 5t), and the pivot portion 5l extends upwardly therefrom to passthrough a hole 73 in the lever 32. The lever 32 is generally plate-likeas clearly shown in Figures 5 and 6, except for an integral opstandingprojection or tooth 7d provided at the right-hand end and a generallysimilar integral tooth Vprovided at the left-hand end. Directingattention irst to the tooth 74, it is clear from Figure 5 that thiselement of the lever 32 is formed for engagement with the notches '62and d3 formed in the cam portion 6l of the associated dial 27. rl`hetooth 75, on the other hand, is positioned `and formed for engagementwith the idler gear 3d which is immediately to the left of theparticular dial member 27. As illustrated, both the Ytooth 7 and thetooth 75 are provided with angularly related faces which engage in thenotches 62 and 63 in the case of the tooth 74 and between the teeth ofthe f.

idler gear 30 in the case of the teeth 75. In either case, it isapparent that rotation of an element with which a tooth 74 or a tooth 75may be engaged is elective to cause displacement of the engaged tooththrough a camming action against an angular face of the tooth. As isclear from Figure 5, however, the positional relationship of the teeth74 and 75 to each other is such that one or the other must beinterlockingly engaged with its respective rotatable member, either thedial 27 or the idler gear 30, in order for the other rotatable member tobe 1 rotated.

The cover 24 has a top 85, side walls $6 and 87, and end walls 88 and89i The top 85 is formed with equispaced arcuate slots 92, adjacent eachof which is a small window opening 93. The window openings 93 enable theresults of computation lto be viewed. vEach arcuate slot 92 defines adisc portion 94 which is joined to the rest of the top by a neck 96.Each Vdisc portion 94 has an integral frusto-conical post dependingtherefrom w lich extends into the Well 46 of the respective post 45 toalign the cover 24 and to provide anchoring support for the disc portion94. Each disc portion 94 has numbers 1 through 9 adjacent the peripheryin clockwise relation opposite nine of the ten wells 67 (Figure 1). ltwill also be noted that numerals l through 9 are formed on the top 85counter-clockwise along the Vouter edge of each arcuate slot 92 oppositenine of the wells 67. The cover 24 is cemented to the base 22.

The idler gears 30 have eight teeth in theY presententbodiment, althoughthey may have a different number.

. d The gear portions 64 of the dial members 27 each have ten teeth sothata transfer of accumulated Vsums takes place at each revolution inaccordance with our arithmetical system.

Figures 10 through 15 illustrate a modified arrangement of the presentinvention in the form of a calculator 100. Inasmuch as the calculatorlb@ is basically similar to the previously described calculator 20,correspending elements in the calculator llltl have been given the samereference numeral that was originally assigned to the elements of thecalculator 20. In the calculator 199, however, these numerals are primedin order to distinguish between the two arrangements.

Considering rs't the case V21 of the calculator 100, the top 24 is inall respects identical with the previously described top 24 of thecalculator 20. The base 22' while generally vsimilar to the base 22differs in minor respects therefrom. One diierence is in the posts`48',which areformed with Athe inset portions 49 "ertending almost the fulllength of the posts. Asis cleartrom Figure 10, Vthe 'portions 49' areadapted to receivefan idler gear 30' having much greater depth than theidler gear 30 of the calculator '29. Another diierence, shown clearlykin Figures 11 'and 12, is in the reloc'ationofthe posts Stas compared tothe posts Sil, and the elimination of the'pivot portions therefrom.lPosts 51 are, on the -other hand, provided at points corresponding tothe location of the portions 5l in the calculator Ztl. VIt will beunderstood that there is a post 51 disposed above and to the right ofeach idler gear Btl'. The height of the posts 51 are, as illustrated inFigure Vl2, such asto provide support for thedetent 28' disposedthereabove. With the detent 2S elevated to a position above the rockinglevers 32', there is of course no requirement for a spring trough in thebase 49. y

The dial member 27', illustrated in Figures 13 and 14, does not includea cam portion as does its corresponding member 27 of the rcalculator2t). The gear portion 64' has nine standard teeth 65' and one tooth 102having an upper section V163 of standard tooth dimension 4'and Va lowersection 104 wherein the tooth is yof shortened depth.

The idler gears 30 also have different upper and'lower sections,therebeing an upper section comprisingitooth portions 105 of standarddimension and lower sections comprising tooth-portions 106 wherein theteeth have shorter depth.

The rocking levers 32 are generally similar to the above-describedrocking levers 32, except that the'le'vers 32' do not have ups'ta'ndingcam portions. In place of these, the levers 32 have the-plate-like bodyextended to form cam projections 74' and 75 shaped as clearlyillustrated in the plan view of Figure 11. Once more, it willbefobs'eived lthat the shape of the cams 74' vand 75 are such as toenable`them to enter between adjacent teeth of the, dial member 27 Vandthe idler gear 3il,'respec tively, lbutto be urged out of suchrelationship when these latfe'r'mmbers are rotated.

Operation ,I It is obvious from the foregoing that the calculators 20and 100 function in respect to addition, subtraction, and-the like,inthe'same manner `as the calculator shown in the applicantsabove-mentioned Patent No. 2,588,539. That is, to add gures in `eitherthe calculator 2G or the calculator 100, units are accumulated on theright hand or'units dial member 27, or 27', tens on the dial Vmember 2701127 immediately to the left thereof, hundreds on theneXt dialV member27 or 27', etc. As clearly set forth in the above-mentioned patent, thedetent 2d or 2:5 functions `in a manner to free or to release forrotation each diall 27 or `27 to the left of the one vwhich -is manuallyrotated, while, at the same time, continuing Vto-impose restraintagainst rotation of dial members 27 or 27"to the right yof that which ismanually rotated. The necessity for releasing the dial members 27 or 27to the left is of course due to the fact that one or more of the dialsmay be required to be rotated by the well-understood operation of thetransfer fingers 60 or 60 and the idler gears 30 or 30 in accumulatingmultiples of ten on the next higher dial. As previously mentioned,however, the very fact that certain of the dials are thus released fromrestraint against rotation makes them susceptible to rotation beyond theintended single position. In other words, vigorous rotative impetusapplied to the manually rotated dial may be transferred with suicientforce to an adjacent dial to cause the latter to rotate past theintended position. The levers 32 and 32 of the present invention servenot as positioning devices to position rotatable elements, but toprevent this inadvertent rotation past the intended point.

Considering first the arrangement of the calculator 20, it is clear fromFigures 4 and 5 that each rocking lever 32 cooperates directly with adial member 27 and with the idler gear 30 immediately to the leftthereof. Inasmuch as each idler gear 30 is continually meshed with thegear portion 64 of the next dial member 27, it may obviously beconsidered that each rocking lever 32 provides interlocking cooperationbetween a pair of adjacent dial members 27.

Directing attention now to the enlarged view of Figure 5, it is clearthat both of the illustrated dial members 27 are restrained againstinadvertent rotation due to the insertion of the detent points 79between adjacent pairs of teeth of the gear portions 64. Assuming,however, that the right 'hand dial member 27 is now manually rotated,the detent 28 will be biased toward the left so that the left handmember 27 will be released each time a tooth 65 of Vthe right handmember 27 passes the associated detent point 70. hand dial member 27 isturned clockwise from the position illustrated in Figure 5, it is clearthat the cam projection 74 will be biased out of the notch 62, and thatthe cam projection 75 will thus necessarily be inserted between twoteeth of the idler gear 36. This will prevent rotation of the latter andhence also of the left hand dial member 27 during the time that theright hand member 27 is rotated one position, or until the next notch 62is in position to receive the cam projection 74. When this lattercondition is satisfied, the rocking lever may again be rocked so as towithdraw the cam projection 75 from between the teeth of the idler gear30, but at this time, it will be noted that the detent point 70 willhave been reinserted between two teeth 65 of the right hand member 27.

From the foregoing, it will be seen that, for the most part, the righthand dial member 27 may be rotated freely with positive assuranceagainst inadvertent rotation of the dial member 27 to its left. However,it is necessary under certain conditions that the rotative movement ofthe right hand member 27 be transferred through the action of thetransfer iinger 60 and the idler gear 30 to the left hand dial member27. This condition is apparent from Figure upon the assumption that theright hand member 27 is to be moved counterclockwise. Such movement ofythe right hand member 27 will cause the transfer finger 60 to engageone of the teeth on the idler gear 30, causing both it and the left handmember 27 to rotate.

As previously mentioned, any rotation of the right hand member 27 biasesthe detent member 28 to the left so as to withdraw the detent point 70from between the teeth 65 of the left hand dial member 27. Also, it willbe noted that counterclockwise movement of the right hand dial member 27from the position illustrated in Figure 5 will cause the cam projection74 again to be biased from the notch 62, but enables it to beimmediately received in the special elongated notch 63. The rotativeimpetus applied to the idler gear 30 by engagement of the transferfinger 60 therewith biases the cam projection 75 out from be- If it beassumed that the right tween the teeth of the gear 30 and enables theleft hand dial member 27 to move under the influence of the finger 60one position. Continued counterclockwise movement of the right hand dialmember 27 moves the notch 63 past the cam projection 74 and thepreviously described interlocked cooperation between the adjacent dialmember 27 is immediately reasserted to prevent passage of the nexttooth. It will be noted that the present invention provides forcontinuous interlocking connection between adjacent dial members throughat least one of three elements, namely, the detent member 28, therocking lever 32, or the transfer nger 60. The interlocked relationshipof the dials which exists even during operation of the calculator byvirtue of the levers 32 prevents the dials from ever jiggling out ofposition. This eliminates, incidentally, the need for brake springs todampen the rotation of dials as shown in my Patent No. 2,588,539.

Considering now the arrangement of the calculator 10), it is obviousthat the general mode of operation is the same as that of the calculator20. Instead of operating in conjunction with a special cam portion,however, the cam 74 operates between the teeth 65 of the dial member 27.Thus, from Figure ll it is apparent that the lever 32 functions similarto its counterpart 32 in the calculator 20. When the right hand dialmember 27 is rotated so as to engage the transfer finger 60 with theidler gear 30 the special tooth portion 104 of shortened depth willenable the lever 32 to be pivoted clockwise sufficiently to enablewithdrawal of the cam 75 from between the shortened teeth 106 of theidler gear 30.

Clearly, there has been provided an anti-spinning construction and amodification thereof which fulll the objects and advantages soughttherefor.

I-t is understood that the foregoing description and the accompanyingdrawings have been given by way of illustration and example. It is alsoto be understood that changes in form of the elements, rearrangement ofparts, and the substitution of equivalent elements, which will beobvious to those skilled in the art, are contemplated as within thescope of the present invention, which is limited only by the claimswhich follow.

What is claimed is:

l. in a calculator, in combination, a case, a plurality of dial membersrotatably mounted in said case, and means movably mounted adjacent saiddial members cooperative therewith to effect computation, said meansincluding primary detent means for releasably retaining said dialmembers in positions of rest and secondary detent means for preventinginadvertent rotation of dials during periods of release from saidprimary detent means.

2. In a calculator, in combination, a oase, a plurality of dial membersrotatably mounted in said case, and means movably mounted adjacent saiddial members cooperative therewith to eifect computation, said meansincluding a detent member for interlockingly connecting adjacent dialmembers in positions of rest and being movable upon rotation of one dialmember to release an adjacent dial member for purpose of computation,and an interlocking member in addition to said detent member forpreventing rotation of said released dial member other than as requiredfor computation.

3. ln a calculator, in combination, a case, a plurality of dial membersrotatably mounted in said case, andmeans movably mounted adjacent saiddial members cooperative therewith to effect computation, said meansincluding detent means for interl-ockingly connecting adjacent dialmembers in positions of rest and being movable upon rotation of one dialmember to release an adjacent dial member for purpose of computation,and means in addition to said detent means for preventing rotation ofsaid released dial member other than as required for computation, saidlatter means including a movable member adapted for selective mutuallyexclusive interlocking connection with each of said adjacent dialmembers.

4. In a calculator, in combination, a case, a plurality asemae of dial'members rotatably 'mounted in said case, and means movably mountedadjacent said dial members vcooperative therewith to eiiectcomputatiomsaid means including detent means for interlockinglyconnecting adjacent `dial members in positions of rest and being movableupon rotation of one dial member to release an adjacent dial member forpurpose of computation, and means in addition to said detent meansforpreventing rotation of said released dial member other than asrequired for computation, said latter means including a rockable leverhaving tooth-like projections at opposite ends, each projection beingadapted for interlocking connection with a respective adjacent dialmember.

'5. Ina calculator, in-combination, a case, a plurality of atleast threeVdial members having successive degrees of computing significancerotatably mountedin said case, and Y'means movably mounted adjacent saiddial members cooperative therewith to effect computation, Vsaid meansincluding 'detent means for interlockingly connecting said plurality ofdial members Vin positions of 'rest and being movable upon yrotation ofany dial of lower degree of computing signiiicance to vrelease forpurpose of computation all dials of higher degree of computingsignicance, and interlocking 'means in addition to said detent means forpreventing rotation of detent released dials other than as required forcomputation.

6. In a calculator, -in combination, a case, a plurality of at leastthree dial Ymembers having successive degrees Y of computingsigniiicance rotatably mounted in said case, and means movably mountedadjacent said dial members cooperative therewith to eect computation,said means including detent means for interlockingly connecting saidplurality of dial members in positions of rest and being movable uponrotation of any Vdial of-lower degree of computing significance toyrelease for purpose of computation all dials of higher degree ofcomputing signicance, and means in addition -to said detent means forpreventing rotation of detent Yreleased dials other than as required forcomputation, said latter means including an individual, movable memberfor each adjacent pair of dial members, said movable members being eachadapted for selective mutually exclusive interlocking connection betweenthe dials of its associated pair thereof.

7. In a calculator, in combination, a case, a plurality of lat leastthree dial members having s-uccessive degrees of computing signiticancerotatably-mounted in said case, and means movably mounted adjacent saiddial members cooperative therewith to effect computation, said meansincluding detent means Vfor interlockingly connecting said plurality ofdial members ill-*positions of rest and being movable Vupon rotation ofany dialof lower degree of computing significance to release Yforpurpose of computation all dials of higher degree of computingsignificance, and means in addition to said-detent means forpreventingrotation of detent released dials other thanv as required forcomputation, --said lattermeans-including an individual rocliableY leverdisposedgenerally between each pair oi' adjacent-dials and havingtooth-like projections at opposite-ends for interlocking connection withrespective dial members.

8 In a calculator, in combination, a case, Va plurality ofdial'membershaving successive degrees of computing significance rotatably mountedinsaid case, each dial member having a transfer Vlinger vand avperipherally notched porton including a gear portion provided with apredetermined number offteeth, an idler gear rotatably disposed betweeneach pair of adjacent dials, each idler gear having teeth enmeshedwiththe gear portion of its associated dial of higher degree ofcomputing significance and engageable by the transfer finger of itsassociated dial of lower degree of computing significance, and anindividual movable member for cooperation with each idler gear and-thedial member of lower degree of computing significance associatedtherewith, each of said movable members being adapted forv mutually.exclusive: interlocking engagement with Vthe particularV idler gear anddial member directly associated therewith. i

9. In a calculator, in combination, a case, a plurality of dial membershaving successive degrees of' computing significance rotatably mountedin said case, each dial member having a transfer finger :and aperipherally notched portion including a gear portion provided with apredetermined number of teeth, an idler gear rotatably disposed betweeneach pair of adjacent dials, each idler gear having teeth enmeshed withthe Ygear portion of its associated dial of higher degree of computingsignicance and engageable by the transfer linger of its associated dialof lower degree of computing signicance, a rocking lever for each idlergear, said levers having tooth-like projections at each end and beingpivotally. mounted so as to enable selective interlocking engagement ofeach with either the teeth of its respective idler gear orthoperipherally notched portion of vthe adjacent dial member of lowerdegree of computing signiticance l0. in a calculatonin combination, -acase, a plurality of dial members having V successive degrees ofcomputing significance rotatably mounted in said case, each dial memberhaving a radially extended transfer iinger and a peripherally notchedportion, said latter portion comprising a cam portion provided withperipherally spaced notches surmounting a gear portion provided with apredetermined number of teeth, there being an identical notch inidentical positional relationship to each of said teeth and an elongatednotch between two adjacent identical notches and in predeterminedpositional relationship to said transferlinger, an idler gear rotatablydisposed between-each pair of adjacent dials, each idler gear havingteeth enmeshed with the gear portion of its associated dial of higherdegree of computing significance and engageable by the transfer `fingerVof its associated dial of lower degree of computing significance, andaurocling lever -for each idler gear, each of said levers havingtooth-like vprojections at each end and being centrally pivotallymounted so Vas to enable one tooth-like projection to be selectivelyinserted between adjacent teeth of the directly associated idler gear`and the other tooth-like projection Yto `be alternatively inserted intoone of the notches of the directly associated` dial, the positionalrelationship .between the vsaid elongated notch and the transfer ringerbeing such that the said other tooth-like projection is receivedrintheelongated notch ,as `the transfer finger engages and moves itsassociated idler gear. e llfThe combination of claim .l0 wherein Vthetoothlike-,projections have angularly related faces to .facilitate thetransfer to the levers of rocking impetuses from the intermittentlyengaged idler gears and cam portions.

:12. `Ina calculator, in combination, a case,` a plurality of dialmembers having successivedegrees of computing significance `rotatablymounted in Ysaid case, Veach dial member having a-radially extendedtransfer nger and a peripherally notched portion, said latter Vportion.comprising a gear-portion provided -with a predetermined niunber ofteeth, one` ofsaid-teeth including asection of short depth, said onetooth being in predetermined positional relationship to said transferfmger, an Yidler gear rotatably disposed between each pair of adjacentdials, each idler gear having teeth enrneshed withthe `gear portion ofits associated dial of vhigher degree of computing signiiicance andengageable by the transferiinger of its associated dial of lower degreeof computing `'signiflcance, and a rocking lever for each idler gear,each of said levers having tooth-like projections ateach end and beingcentrally pivotally mounted so as to `enableone tooth-like projectionVto be selectively inserted between adjacent teeth of the directly`associated idler gear and the other tooth-like projection tobealternativelyinserted betweenadjacent teeth, except the tooth having asection off-short depth, of the gear portion of the `directly associateddial, the positional relationship between the said tooth having a`section of short depth `and the transfer iinger being such that thesaid other tooth-like projection passes over the section of short depthas the transfer finger engages and moves its associated idler gear.

13. The combination of claim 12 wherein the toothlike projections haveangularly related faces to facilitate the transfer to the levers ofrocking impetuses from the intermittently engaged idler gears and gearportions.

14. In a calculator, in combination, a case, a plurality of dial membershaving successive degrees of computing significance rotatably mounted insaid case, each dial member having a transfer finger and a peripherallynotched portion including a gear portion provided with a predeterminednumber of teeth, an idler gear rotatably disposed between each pair ofadjacent dials, each idler gear havingI teeth enmeshed with the gearportion of its associated dial of higher degree of computingsignificance and engageable by the transfer finger of its associateddial of lower degree of computing significance, detent mechanism adaptedfor simultaneous interlocking connection with the several dial membersfor restraining them against inadvertent rotation, said detent mechanismbeing movable upon rotation of any dial of relatively low degree ofcomputing significance in a manner to release its restraint upon alldials of higher degree of computing significance, and an individualmovable member for cooperation with each idler gear and the dial memberof lower degree associated therewith, each of said movable members beingadapted for mutually exclusive interlocking engagement with theparticular idler gear and dial member directly associated therewithwhereby each of the dial members released from the inuence of the detentmechanism is prevented from rotation other than in accordance withcorresponding rotation of the dial member of next lower degree ofcomputing significance.

15. The combination of claim 14, wherein the notched portion of eachindividual dial member is formed to enforce a locked condition of thedial member of next higher degree of computing significance duringrotation of the individual dial member through at least part of eachangular increment equal to the angular spacing of teeth on the gearportion, except the particular angular increment during which thetransfer finger engages the teeth of the idler gear.

References Cited in the file of this patent UNITED STATES PATENTS2,588,539 Kesling Mar. 1l, 1952

